Percussion igniting device for clockwork fuses



Feb. 11', 1941.

* H. JUNGHANS PERCUSSION IGNITINGDEVIiCE FOR cLocxwonx FUSES Filed July 1, 193s HEL'MUT .7/71 9/7/0/7: Ju N'G HA N3 Patented Feb. 11, 1941 PATENT OFFICE PERCUSSION IGNITING nnvrcn Foa cnocxwonx rusns Helmut JnnghansJSchramberg-Sulgen, Eckenhof, Wurttember-g; Germany Application July 1, 1938, Serial No. 217,011

In Germany August 3, 1935' 4 Claims.

with a self-destructive time device, for the purpose of breaking-up the projectile while still in the air, in the event of its missing the target.

This last-mentioned self destructive device is set for an unalterable period of time, which need not be absolutely precise. For this reason, there was no difficulty in arranging the barrel-safety device and the field or muzzle safety device, in such a way that the striking pin passed through the hub of the balance wheel, and served as a shaft for the latter. It was desired to increase the friction of the balance-wheel bearing, for producing a braking action, which necessitated the use of a strong pin.

In the case of clockwork fuses working as precision time fuses it is necessary that the balance wheel should be centrally mounted with respect to the fuse, and also that the strikingpinshould be arranged in the longitudinal axis of the fuse,

so as to pierce the detonator cap properly. In the contrary, to self-destructive impact fuses the aim in view is to minimize the friction-in the balance-wheel bearing, that is to say, the balance wheel must be mounted on a very slender shaft. Accordingly, the invention is based on the problem of making the striking pin as slender as possible at the part where it passes through the hub of the balance wheel. The only way, in which this problem can be solved is to provide a striking pin which is as slender either throughout its length, oronly at its end portion, as required for the mounting of the balance wheel. Even subdividing the striking pin into several parts, as is known in the case of self-destructive impact fuses, would not leadto the desired result, since, when firing the shot, the'entire pin would be subjected to compression stress, as far 0 as the timesafety device was concerned. Ac-

cording to the present invention, the several parts are or locked individually by independent devices, barrel and transport safety devices for example. With such a construction, the end part can be so slender that the timing accuracy ofthe balance wheel is not impaired by friction, and moreover, the pin can no longer bend, thereby impeding the movement of the central wheel of the fuse, nor can the end, carrying the balance wheel of the pin become deflected and the regu- 5 -lator become disturbed;

Other features and advantages of the inven tion will be gathered from the following description and accompanying drawing of a typical embodiment of the invention, in which:

Fig. 1 is a longitudinal axial section throug a clockwork fuse, only such parts of the impact ignition device and pinion gear being shown as are necessary for understanding the invention.

Fig. 2, shows the fieldsafety device coacting 15 with the ignition portion of the striking pin, and

Fig. 3 represents the striking pin.

The ignition device 0 is in the casing a, b of the fuse. The typical embodiment shown is a mechanical (clockwork) time fuse also highly sensitive to impact. The igniter 11 extends centrally, from the nose (not shown) as far as the detonator cap e. -The ignition pin (1 (see Fig. 3) is dividal into three parts, the first part d1v of which, the so-called impact member, rests at its lower part on the head of the second part, (12 the socalled transmission member, and is guided in a sleeve d'z, surrounding the latter. The lower end-of the transmission member d2 is above, the so-called striker pin dz, which acts upon the detonator cap e. The impact member di and transmission member (is are supported by the cheeks f, of the barrel-safety device, which engage the sleeve (1's, in known manner. The barrel safety device operates to prevent ignition of the fuse while the projectile is in the barrel of the gun. The striker pin (is in turn is seated, by means of its collar d'a, on the segment a of the field-safety device, gearing, by means of the tooth 171, with its control pinion h. The bottom end of the transmission member dz, and the head end of the striker pin da, are guided in an axial bore .of the shaft i of the center wheel. The slender lower end d3 of the striker pin acts as 45 the shaft upon which is mounted the balance wheel I: provided with a bored hub l. The ignition device for the timing mechanism is independent of that for the impact mechanism, m denoting the striking pin and n the detonator 0 cap of the said timing mechanism. The construction of this mechanism is immaterial to the invention. The sub-divisionof the ignition pin (1 into several parts is also of considerable advantage from the point bf view of manufacture,

as it would be a troublesome matter to make an ignition pin comprising the three parts (21, d2. d:

or even one with only the two parts dz and (13. A

pin of such length is liable to be not quite straight and to seize in its guide, whereby it might fail to work properly or affect other operations. This would be specially feared in the case of the through portion d3 which carries the balance wheel is. The subdivision of the ignition pin into several short parts, and the securingy of said parts by separate safety devices, which may .be of correspondingly light construction, is ya sisting of the combined weights of the parts d: v

and (Z2. I

The impact ignition device functions in the following manner. After the rotary movement of the projectile has been started by flringtheshot, the two cheeks f of the barrel-safety device fly apart, under the action of centrifugal force, but only after the projectile has issued from the barrel. Until then, and during the propulsion of the projectile within the barrel the transmission member (12, by its inertia, forces its projection 12, into the recesses q of the cheeks f, as shown in Fig. 1 with such force as to maintain them in position despite the rotary movement. After separation of the checks 1, the impact and transmission members are now free, whereas, the ignition member (is is still restrained by the field safety segment 9. Directly the projectile leaves the barrel, the clockwork for the precision timing begins to run, and the pinion h shown in Fig. 2 pushes the field safety segment g'from under the collar d: of the striker pin dz, so that the fuse becomes set for ignition timed to occur after the projectile has traversed the required distance corresponding to the setting of the clockwork, or, if the projectile should hit the shaft for said balance wheel, and a second safetarget before the clockwork releases the pin da,

I the impact pin d, will determine the ignition by acting through the aligned parts (12, (13.

Having now particularly described and ascertained the nature of my said invention and in 6 what manner the same is to be performed, I declare that what I claim is: r I

1. A clockwork fuse for artillery projectiles comprising, precision clockwork including a balance wheel, an impact ignition pin, safety means so constructed and arranged as to normally engage saidimpact ignition pin but releasing it at the end of the acceleration of the projectile; a detonator \in alignment with said impact ignition pin, a striker pin of substantially smaller diameter than said impact ignition pin and disposed in alignment with the latter and between it and the detonator, said striker pin forming a ty means so arranged as to engage said striker pin at least until the end of said acceleration period, said impact and striker pins being arranged in the longitudinal axis of the fuse.

2. A clockwork fuse. for artillery projectiles comprising. precision clockwork including a balance wheel, ignition means including a detonator and a plurality of separate aligned pins arranged in the longitudinal axis of :the fuse, one of said pins being a relatively massive impact pin and 6 another of said pins being-a light and slender striker pin cooperating with .the detonator and forming a shaft for said balance wheel, and a separate and independently operative safety device engaging each of said impact and striker 35 pins of said ignition means.

3. A clockwork fuse accordingtc claim 2, in which a transmission pin is provided between the impact member and the striker pin.

4. A clockwork fuse according to claim 2, in 0 which a transmission pin is provided between the impact pin and the striker pin, and in which a sleeve is provided connecting said impact pin to the transmission pin, said sleeve being engaged by a safety device. 45

HELMUT JUN GHANS. 

